Constitutive modelling and numerical simulation of multivariant phase transformation in superelastic shape‐memory alloys

This work concerns the micromechanical constitutive modelling, algorithmic implementation and numerical simulation of polycrystalline superelastic alloys under multiaxial loading. The model is formulated in finite deformations and incorporates the effect of texture. The numerical implementation is based on the constrained minimization of the Helmholtz free energy with dissipation. Simulations are conducted for thin tubes of Nitinol under tension–torsion, as well as for a simplified model of a biomedical stent. Copyright © 2004 John Wiley & Sons, Ltd.     

Linear B-cell epitopes in the N-terminus of L2 of bovine papillomavirus type 4

In vivo dosimetry performed with semiconductor detectors is a reliable method for patient dose control. The purpose of this study is to evaluate the perturbations introduced in the patient's absorbed dose distribution by three types of commercially available diodes (Isorad, Sun Nuclear Corp.; model 114200, 114300 and 114400) from the same company and to present possible solutions for minimizing this side-effect.     

Giant plexiform schwannoma: a report of two cases with soft tissue and visceral involvement

We report two cases of massive, solitary, plexiform schwannoma. One was a 9-cm subcutaneous lesion on the hip of a 72-year-old man who had become aware of the slow-growing tumor 50 years earlier; the other is the first reported plexiform schwannoma to arise in a visceral organ: it arose in the ascending colon of a 54-year-old man and exhibited a dumbbell configuration with submucosal and subserosal components. Neither patient had neurofibromatosis or schwannomatosis. Both tumors were well-circumscribed and multinodular, and both showed a plexiform architecture. Microscopically, the nodules were composed primarily of Antoni A tissue, replete with nuclear palisading and Verocay bodies. Examination by immunohistochemistry and electron microscopy demonstrated the features of well-differentiated Schwann cells; nodules were surrounded by attenuated, residual perineurium. Both patients followed a benign clinical course, without recurrence or metastasis. Neither the large tumor size nor the unusual locations affected the biologic behavior of these neoplasms. A massive plexiform schwannoma must be distinguished from a malignant peripheral nerve sheath tumor and from a plexiform neurofibroma, a tumor prone to malignant transformation.     

Effect of prepartum bovine somatotropin in primigravid ewes on mammogenesis, milk production, and hormone concentrations

Twenty-five primigravid ewes were used to investigate the effect of bST, between 97 and 124 d of gestation, on mammogenesis and subsequent milk production. Five ewes (reference group) were slaughtered at 96 d of gestation, and the remaining ewes were injected daily with saline (control group: n = 10) or .1 mg/kg of BW of bST (bST group: n = 10). Following bST treatment, 5 control and 5 bST group ewes were slaughtered (slaughter group). The remaining ewes were slaughtered after lambing and being milked for 8 wk (production group). Weekly blood samples were obtained from both slaughter and production group ewes. Slaughter group ewes were also subjected to 8-h serial blood sampling at 98 d (period 1) and 123 d (period 2) of gestation. Milk production was 42% higher in ewes treated prepartum with bST than in those treated with saline. Results suggest that the increase in milk was due to an increase in mammary parenchymal cell number rather than to an increase in cellular activity. The high rate of [3H]thymidine incorporation into parenchymal tissue in reference group ewes suggests that the increase in parenchyma during the second trimester of gestation is due to cellular hyperplasia but that cellular hypertrophy may be more important during the last trimester. Plasma IGF-I concentrations were significantly higher during bST treatment and remained elevated between daily injections; the increase was greatest in period 2.     

Impact of maternal alcoholism on separation of children from their mothers: findings from a sample of incarcerated women

Research on achievement goal orientation in sport has relied primarily on traditional statistical methodology to examine group mean differences. Unfortunately, examination of the measurement model is generally ignored prior to means testing. This study reports an application of structural equation modeling (SEM) in testing measurement invariance and latent mean structure of the Task and Ego Orientation in Sport Questionnaire (TEOSQ; Duda & Nicholls, 1989) using male and female college students. A confirmatory factor analysis for testing invariance revealed invariant measurement properties and factor structures across gender, indicating that task and ego orientation are similarly conceptualized by male and female students. Subsequent testing of latent mean structures, however, showed significant gender differences with respect to ego orientation, but no difference in task orientation. The SEM procedures used in the present study demonstrate additional construct validity and internal consistency reliability for the TEOSQ and, by confirming its factor structure, provide a sound psychometric basis for its continued use in substantive studies focusing on the comparison of achievement goal orientation across gender.     

Community OR — Five Years of Organised Activities and Beyond

What has become known as Community Operational Research has been around in the UK for many years. The election of Jonathan Rosenhead as President of the UK OR Society in 1986–87 was the catalyst for bringing together and expanding activities which had been carried out largely by individuals working in isolation on a voluntary basis. The following five years have seen the establishment of the Community OR Unit at Northern College, the Centre for Community OR at Hull University and the Community OR Network, which supports the activities of volunteer OR workers across the UK. This paper reviews the range and types of work which have been undertaken by various practitioners. An assessment of the success of community OR is made and a number of issues which have arisen are discussed. Finally, given the diverse nature of community OR, its practice and practitioners, there is some discussion about the future of the area.     

Development of an animal model for across-herd genetic evaluation of number born alive in swine

An animal model and computer software were developed to conduct across-herd genetic evaluations using data from producers participating in the Sow Productivity Index program of the American Yorkshire Club. The final data set consisted of 61,596 litter records from 1986 to early 1990. The animal model included fixed contemporary group effects and random additive direct, service sire, permanent environmental, and residual effects. Additive genetic relationships among animals were included. A separate relationship matrix for service sires and their sires was also included. A data set similar to the Yorkshire field data was simulated to use in testing the animal model. The simulated data set consisted of 40 herds, each with 120 reproducing dams and either four or five sires. Six generations of simulated data were produced, resulting in 20,605 litter records. These records were then evaluated using the animal model for number of pigs born alive. Finally, correlations between the true breeding values from the simulation and the predicted breeding values were computed. The correlation between the 918 true and predicted sire breeding values was considerably lower for the animal model without a service sire effect than when it was included (.53 vs .74, respectively). However, the difference was cut in half (.66 vs .77) when only sires with greater than five daughter records were included. The high accuracy of the animal model with a random service sire effect indicates that the proposed model adequately accounts for the variation found in records for number of pigs born alive.     

X-ray-based measurement of composition during electron beam melting of AISI 316 stainless steel: Part II. Evaporative processes and simulation

An energy dispersive X-ray (EDX) detector mounted on a laboratory scale electron beam furnace (30 kW) was employed to assess the potential use of X-rays as a means of on-line composition monitoring during electron beam (E B) melting of alloys. The design and construction of the collimation and protection systems used for the EDX are described in Part I. In Part II, a mathematical simulation of the heat, mass, and momentum transfer was performed for comparison to the EDX and vapor deposition results. The predicted flow patterns and evaporation rates are used to explain the differences between the two experimental methods. For the EDX spectra measured, the X-rays generated were from the center of the hearth where fluid flow rising from the bulk of the pool is sufficient to maintain the bulk composition despite the high evaporative flux from the surface. The flow moves radially outward from the center of the pool, with the volatile species being depleted. The vapor deposition technique measures the entire region, giving an average surface composition, and it therefore differs from the EDX results, which gave a near bulk composition. This combined study using in-situ EDX measurements and numerical simulations both provided an insight into the phenomena controlling the evaporation in an EB-heated system and demonstrated the viability of using EDX to measure the bulk composition during EB melting processes.